Where do they store the water? In NYC it's not uncommon for a building to have a holding tank on the roof of the building and then use gravity to supply "pressure" to the units in the building. If Singapore does something similar, it would be logical that the water would be warmer.

I lived on the top floor in a newer building in Dallas that pumped water the entire way and the pressure was noticeably less in my apartment than in the gym on the ground floor. The water was "cold" though!